An anxious spill-over crowd in a nearby auditorium joined in the loud celebration.

New Horizons zoomed past the small celestial object known as Ultima Thule 3 ½ years after its spectacular brush with Pluto. Scientists say it will take nearly two years for New Horizons to beam back all its observations of Ultima Thule, a full billion miles (1.6 billion kilometers) beyond Pluto.

At that distance, it takes six hours for the radio signals to reach Earth.

A NASA spacecraft opens the new year at the most distant world ever explored, a billion miles beyond Pluto.

NASA spacecraft zips by most distant world ever studied

A NASA spacecraft on Tuesday flew past the most distant world ever studied by humankind, Ultima Thule, a frozen relic of the early solar system that could reveal how planets formed.

"Go New Horizons!" said lead scientist Alan Stern as a crowd cheered at the Johns Hopkins Applied Physics Laboratory in Maryland to mark the moment at 12:33 am (0533 GMT) when the New Horizons spacecraft aimed its cameras at the space rock four billion miles (6.4 billion kilometers) away.

"Never before has a spacecraft explored something so far away."

The spaceship was to collect 900 images over the course of a few seconds as it shaved by at a distance of about 2,000 miles (3,500 kilometers).

"Now it is just a matter of time to see the data coming down," said deputy project scientist John Spencer of the Southwest Research Institute.